The separation of some mixed alkylated phenols is very difficult when applying common separation methods, such as, distillation, extraction, crystallization, etc.; due to their close boiling points, polarities and densities. It has been found that some mixtures of alkylated phenols can be separated based on the differences in their dissociation constants utilizing dissociation extraction techniques.
The conventional dissociation extraction techniques require the alkylated phenols be in a water-immiscible organic solvent which is treated with a strong basic aqueous solution to selectively neutralize the alkylated phenol having the higher dissociation constant and form an ionized salt. The alkylated phenol in salt form is absorbed into the aqueous phase. The aqueous phase is then separated from the organic phase and treated with a mineral acid to regenerate the alkylated phenol from the ionized salt form. Hence, conventional dissociation extraction techniques present disadvantages in the continual consumption of strong base and mineral acid, in the handling of mineral acid and in the production of waste water.
The process comprising this invention overcomes the disadvantages of continual consumption of acid and base, the continual production of waste water and the handling of acid when separating alkylated phenols based on the differences in their dissociation constants.